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In this Nov. 6, 2017, file photo, law enforcement officials investigate the massacre at the First Baptist Church of Sutherland Springs in Sutherland Springs, Texas. On Nov. 5, a gunman, Devin Patrick Kelley, killed 26 people at the church and wounded 20 others when he opened fire during a Sunday service.

The wife of the man who opened fire at a Texas church last November, killing more than two dozen people before killing himself, says he tied her to their bed before leaving for the shooting.

In a series of interviews with the San Antonio Express-News, Danielle Kelley said her husband, Devin Kelley, behaved strangely detached that morning until he put their 2-year-old son in the bedroom and forced her into the bedroom, where he bound her to the bed using rope, handcuffs and tape as their son cried.

She said Devin told her he loved her, kissed their 5-month-old daughter in her crib and told their son, "I'll be right back." He grabbed his rifle and two handguns, donned military-style tactical gear and body armor, then left. Devin Kelley then went to First Baptist Church in Sutherland Springs and killed 25 people, more than half of whom were children. Authorities put the official death toll at 26 because one of the victims was pregnant.

Danielle still uses her husband's surname, saying she's "not going to be ashamed" of it.

Her adoptive mother, Michelle Shields, has said her son-in-law was controlling and abusive to her daughter, who often accepted the abuse.

"We all have our demons," Danielle said.

Danielle and Devin met when she was 13 and he was 17. Both came from unstable backgrounds. Danielle said her biological parents had abused her before Child Protective Services removed her and Michelle Shields adopted her as a 4-year-old. She said Devin told her about being bullied as a child.

After he joined the Air Force and married another woman, they corresponded through letters. He was court-martialed for fracturing his stepson's skull, served time behind bars, was kicked out of the military and divorced.

Devin and Danielle married in April 2014, when he was 23 and she was 19. She said he went with her everywhere.

"It was frustrating. But you would be surprised, when everything's gone, how much I miss it," she said.

Six months before the massacre, while living in Sutherland Springs, about 30 miles southeast of San Antonio, Devin grew more depressed, his temper grew shorter, and he grew less tolerant, she said. "He was shutting down," Danielle said.

In April 2016, he bought an assault-style rifle and gathered more than a dozen magazines capable of holding 30 rounds of ammunition each. He grew more reclusive.

When she persuaded him to attend church services, including at First Baptist, he would laugh during sermons. He became an atheist.

"Devin was sick. He lost who he was. Because the real Devin would've never hurt babies. He was a family person. He would never have hurt anybody. He lost touch of reality," Danielle said.

After the shooting, he called his parents and told them to go to his house. He later frantically phoned Danielle, who put the call on speakerphone for his parents, who had untied her.

"I just shot up the Sutherland Springs church," he said. They pleaded with him to stop. "He was like `I can't. I've killed so many people -- so, so many people,"' Danielle said. "He kept saying how sorry he was."